The present invention relates to improvements in apparatus for collecting fish eggs.
Conventionally, fish eggs were collected from the bodies of fishes such as walleye pollack primarily by manual work. Since the manual work is very inefficient, apparatus have been developed in recent years for mechanically collecting fish eggs.
Apparatus heretofore known for collecting fish eggs include, for example, the one disclosed in Examined Japanese Patent Publication No. 26257/1984.
The disclosed apparatus comprises a conveyor for transporting fish thereon with their abdomens directed toward the direction of advance of the conveyor and with the tails held to the conveyor, and egg removing spatulas arranged along the path of transport of fish horizontally pivotally movably and each biased by a spring toward the abdominal side of the fish. With the advance of the fish, the spatula slidingly moves relative to the fish toward its head in contact with the abdomen, whereby fish egges are pushed out from the abdominal cavity of the fish toward its head.
However, the apparatus has the problem that when coming into contact with the fish, the spatula merely slides along in contact with the abdomen of the fish if the spring force is weak, almost failing to remove the fish eggs from the abdominal cavity. Another problem is also encountered in that if the spring has an excessive force, the fish will be bent rearward to escape under great pressure of the spatula, with the result that the spatula fails to fully engage in the abdomen and to force out the eggs efficiently.
With the above apparatus, therefore, the spatula is disposed at more than one location along the conveyor to ensure reliable collection of fish eggs. This arrangement makes the apparatus large-sized, necessitating a large space for the installation of the apparatus. Moreover, collection of fish eggs at the plurality of locations entails the problem of a reduced collection efficiency.
Further with the above apparatus, the spatulas are arranged at the specified positions, while fish are transported in different positions. The spatula therefore not infrequently comes into contact with the midportion of the abdomen of the fish, collapsing many eggs to impair the commercial value of the product and encountering difficulty in collecting fish eggs.